/*
 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
 *
 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
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 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
 *
 * This license is subject to the following condition:
 *
 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must be included in all copies or substantial
 * portions of the Software.
 *
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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package com.oracle.truffle.api.impl;

import com.oracle.truffle.api.Truffle;
import com.oracle.truffle.api.TruffleOptions;
import java.nio.file.Path;
import java.util.Map;

public abstract class HomeFinder {

    private static HomeFinder nativeImageHomeFinder;   // effectively final after native image
                                                       // compilation

    public abstract Path getHomeFolder();

    public abstract String getVersion();

    public abstract Map<String, Path> getLanguageHomes();

    public abstract Map<String, Path> getToolHomes();

    public static HomeFinder getInstance() {
        if (TruffleOptions.AOT) {
            return nativeImageHomeFinder;
        }
        return Truffle.getRuntime().getCapability(HomeFinder.class);
    }

    /**
     * Looks up the {@link HomeFinder} instance.
     *
     * NOTE: this method is called reflectively by downstream projects.
     *
     */
    @SuppressWarnings("unused")
    private static void initializeNativeImageState() {
        assert TruffleOptions.AOT : "Only supported during image generation";
        nativeImageHomeFinder = Truffle.getRuntime().getCapability(HomeFinder.class);
    }

    /**
     * Cleans the {@link HomeFinder} instance.
     *
     * NOTE: this method is called reflectively by downstream projects.
     *
     */
    @SuppressWarnings("unused")
    private static void resetNativeImageState() {
        assert TruffleOptions.AOT : "Only supported during image generation";
        nativeImageHomeFinder = null;
    }
}
